Rheological Properties and Gelcasting Behavior of Ultrafine ZrO2 Suspension

2008 ◽  
Vol 368-372 ◽  
pp. 740-743
Author(s):  
Jin Feng Wang ◽  
Ya Chun Gao ◽  
Xian Feng Yang ◽  
Jia Lin Sun ◽  
Zhi Peng Xie
Keyword(s):  
Zeta Potential ◽  
Rheological Properties ◽  
Influencing Factors ◽  
Milling Time ◽  
Ph Value ◽  
Ceramic Materials ◽  
Solid Loading ◽  
High Solid Loading ◽  
Upper Limit ◽  
Minimum Viscosity

Ultrafine ZrO2 suspension with stable high solid loading was prepared, and ZrO2 ceramic materials with uniform structures were fabricated through gelcasting. Zeta potential of the ultrafine ZrO2 suspensions with A-type dispersant, triammonium citrate, and without dispersant was measured. The influencing factors on suspension flowability as the content of dispersant, pH value, solid loading, and milling time were studied in detail. And the optimum premixed solution/initiator (APS)/catalyst (TEMED) ratio for gelcasting was investigated. The results showed that A-type dispersant was suitable for dispersing of ultrafine ZrO2 particles in aqueous premixed solutions; the optimized content of dispersant was 2%~2.5% of ZrO2 volume; ZrO2 suspension displayed a minimum viscosity at pH 10.66; the upper limit of solid loading was 54vol.%; and the appropriate milling time was 12 hours. When premixed solution/initiator (APS)/catalyst (TEMED) ratio was 100/1/0.5, ZrO2 suspension has a better gelcasting behavior.

Fabrication and Characterization of Sr0.7Ca0.3TiO3 Substrates Using Aqueous Tape Casting Process

2010 ◽  
Vol 434-435 ◽  
pp. 275-277
Author(s):  
Wei Liang Liu ◽  
Shuo Qi Liu ◽  
Du Song Mao
Keyword(s):  
Zeta Potential ◽  
Ph Value ◽  
Tape Casting ◽  
Casting Process ◽  
Solid Loading ◽  
Potential Measurement ◽  
Binder Ratio ◽  
Rheological Test ◽  
Test Result

Sr0.7Ca0.3TiO3 (SCT) substrates were prepared through aqueous tape casting. Properties of SCT slurries with and without ammonium polyacrylate (NH4PAA) dispersant were characterized by zeta potential. The zeta potential measurement result shows that the isoelectric point (IEP) of the powder changed obviously with the addition of the dispersant. The optimum pH value of the slurry is in the range of 9-10. The rheological test result indicates that the proper content of the dispersant is between 0.6 and 0.8 wt%. The effect of different plasticizer/binder ratio (R) on the properties of the green tapes was investigated. For 56 wt% solid loading, the tensile strength of the green tape reached 2.02 MPa and the breaking elongation rate was about 8%. SEM micrographs show that the microstructure of the green tapes is homogeneous and the microstructure of the sintered tapes is dense.

Rheological Properties and Stability Characteristics of Biochar-Algae-Water Slurry Fuels Prepared by Wet Milling

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Pengfei Liu ◽  
Mingming Zhu ◽  
Zhezi Zhang ◽  
Dongke Zhang
Keyword(s):  
Rheological Properties ◽  
Chlorella Vulgaris ◽  
Sodium Salt ◽  
Apparent Viscosity ◽  
Milling Time ◽  
Solid Loading ◽  
Wet Milling ◽  
Pine Sawdust ◽  
Acid Sodium Salt ◽  
Lignosulfonic Acid

This study was aimed to understand the rheological properties and stability characteristics of biochar-algae-water (BAW) slurry fuels prepared by wet milling. A pine sawdust biochar and a chlorella vulgaris algae were used in preparing the slurry fuels. The BAW slurries were formulated by mixing the biochar, algae, de-ionized water, lignosulfonic acid sodium salt, and then the mixture was ball-milled for various times. The BAW slurries with a constant solid loading of 45 wt % were prepared with varied algae proportion in algae/biochar mixture. The apparent viscosity and stability of BAW slurries were measured. It was found that D50 of the particles of the solid in the slurries decreased with increasing milling time. The viscosity of the slurries decreased first and then increased as milling time increased, reaching a minimal value when D50 of the solid was between 3 and 7 μm. The lowest viscosity of BAW slurries achieved at a given solid loading increased with increasing the algae proportion in the solid. The BAW slurries showed better stability at higher algae proportions due to enhanced flocculation.

Rheological Properties Analysis of WC-Co Injection Feedstock

2013 ◽  
Vol 773-774 ◽  
pp. 880-886 ◽  
Author(s):  
Sri Yulis M. Amin ◽  
Norhamidi Muhamad ◽  
Khairur Rijal Jamaludin
Keyword(s):  
Rheological Properties ◽  
Rheological Behaviour ◽  
Critical Factor ◽  
Palm Stearin ◽  
Solid Loading ◽  
Binder System ◽  
Capillary Rheometry ◽  
High Solid Loading ◽  
Flow Behaviour Index ◽  
Behaviour Index

In order to produce a defect-free component, the feedstock composition plays as a critical factor. The feedstock needs to meet the following criteria; high solid loading with excellent flowability. The flowability of the feedstock is greatly determined by the rheological response. Therefore, the aim of this paper is to investigate the rheological behaviour of MIM feedstock comprising of WC-Co powder, with a binder system of Palm Stearin (PS) and Polyethylene (PE), by means of a capillary rheometry. The viscosity and shear rate of various feedstocks at powder loading ranging from 59, 61 and 63% were measured at L/D = 10 die. The rheological properties such as flow behaviour index, activation energy and moldability parameter of each feedstock were calculated and from the analysis, it was concluded that they show a good pseudo-plastic behaviour within acceptable ranges in MIM.

scholarly journals Additive manufacturing of thin electrolyte layers via inkjet printing of highly-stable ceramic inks

2021 ◽  
Author(s):  
Zhongqi Zhu ◽  
Zhiyuan Gong ◽  
Piao Qu ◽  
Ziyong Li ◽  
Sefiu Abolaji Rasaki ◽  
...  
Keyword(s):  
Inkjet Printing ◽  
Polyacrylic Acid ◽  
Storage Period ◽  
Structural Quality ◽  
Solid Loading ◽  
Ultrasonic Dispersion ◽  
Promising Alternative ◽  
Printing Process ◽  
High Solid ◽  
High Solid Loading

AbstractInkjet printing is a promising alternative for the fabrication of thin film components for solid oxide fuel cells (SOFCs) due to its contactless, mask free, and controllable printing process. In order to obtain satisfying electrolyte thin layer structures in anode-supported SOFCs, the preparation of suitable electrolyte ceramic inks is a key. At present, such a kind of 8 mol% Y2O3-stabilized ZrO2 (8YSZ) electrolyte ceramic ink with long-term stability and high solid loading (> 15 wt%) seems rare for precise inkjet printing, and a number of characterization and performance aspects of the inks, such as homogeneity, viscosity, and printability, should be studied. In this study, 8YSZ ceramic inks of varied compositions were developed for inkjet printing of SOFC ceramic electrolyte layers. The dispersing effect of two types of dispersants, i.e., polyacrylic acid ammonium (PAANH4) and polyacrylic acid (PAA), were compared. The results show that ultrasonic dispersion treatment can help effectively disperse the ceramic particles in the inks. PAANH4 has a better dispersion effect for the inks developed in this study. The inks show excellent printable performance in the actual printing process. The stability of the ink can be maintained for a storage period of over 30 days with the help of initial ultrasonic dispersion. Finally, micron-size thin 8YSZ electrolyte films were successfully fabricated through inkjet printing and sintering, based on the as-developed high solid loading 8YSZ inks (20 wt%). The films show fully dense and intact structural morphology and smooth interfacial bonding, offering an improved structural quality of electrolyte for enhanced SOFC performance.

scholarly journals A Novel Approach to Fabricate Foam Ceramics from Steel Slag

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Yu Zheng ◽  
Xudong Luo ◽  
Jinlong Yang ◽  
Wenlong Huo ◽  
Chi Kang
Keyword(s):  
Compressive Strength ◽  
Ph Value ◽  
Steel Slag ◽  
Raw Material ◽  
Solid Loading ◽  
Insulation Material ◽  
Ceramic Foams ◽  
Novel Approach ◽  
The Stability ◽  
First Time

A novel approach is used for fabricating steel slag foam ceramics based on the particle-stabilized foaming method. In this work, steel slag was used as the raw material and propyl gallate (PG) was used as the surface modifier. For the first time, steel slag ceramic foams were successfully fabricated based on particle-stabilized foams. The results show that the stability of the ceramic foams was closely related to the pH value and PG concentration. The porosity and compressive strength could be controlled by changing the solid loading of steel slag and sintering temperature. The porosity of steel slag foam ceramics ranged from 85.6% to 62.53%, and the compressive strength was from 1.74 MPa to 10.42 MPa. The thermal conductivity of steel slag foam ceramics was only 0.067 W (m·K)−1, which shows that it could be used as a thermal insulation material.

Preparation of Sands Modified by Aluminous Salt and its Adsorption Capability of CD2+

2011 ◽  
Vol 130-134 ◽  
pp. 856-859
Author(s):  
Chun Sheng Ding ◽  
Yang Ping Fu ◽  
Qian Fen Zhu ◽  
Jing Fu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Influencing Factors ◽  
Removal Efficiency ◽  
Specific Surface Area ◽  
Quartz Sand ◽  
Ph Value ◽  
Alkaline Condition ◽  
Initial Concentration ◽  
Adsorption Capability

In this experiment quartz sand was chosen as a carrier to be coated by aluminous salt under alkaline condition, and then the specific surface area was tested, and the adsorption capability and Cd2+ removal influencing factors of modified sand were studied. The investigation results showed that the specific surface area of modified sand was 75.244m2/g which was 9.38 times of that of original sand; the removal efficiency of Cd2+ by aluminous salt modified sand reached 59% contrast to 39% of original sand with pH 7.00. It was also found that the removal efficiency of Cd2+ by the aluminous salt modified sand was reduced with the increase of initial concentration of Cd2+ solution, and was enhanced with the increase of pH value, the Cd2+ removal efficiency was almost 71% with pH 9.0.

scholarly journals Validation of high performance liquid chromatography method for determination of meloxicam loaded PEGylated nanocapsules

2015 ◽  
Vol 51 (4) ◽  
pp. 823-832 ◽  
Author(s):  
Francine Rodrigues Ianiski ◽  
Luciane Varini Laporta ◽  
Alexandre Machado Rubim ◽  
Cristiane Luchese
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Zeta Potential ◽  
Analytical Method ◽  
High Performance ◽  
Ph Value ◽  
Hplc Method ◽  
Polydispersity Index ◽  
Size Distributions ◽  
Relative Standard

abstract A method to ensure that an analytical method will produce reliable and interpretable information about the sample must first be validated, making sure that the results can be trusted and traced. In this study, we propose to validate an analytical high performance liquid chromatography (HPLC) method for the quantitation of meloxicam loaded PEGylated nanocapsules(M-PEGNC). We performed a validation study, evaluated parameters including specificity, linearity, quantification limit, detection limit, accuracy, precision and robustness. PEGylated nanocapsules were prepared by interfacial deposition of preformed polymer, and the particle size, polydispersity index, zeta potential, pH value and encapsulation efficiency were characterized. The proposed HPLC method provides selective, linear results in the range of 1.0-40.0 μg/mL; quantification and detection limits were 1.78 μg/mL and 0.59 μg/mL, respectively; relative standard deviation for repeatability was 1.35% and intermediate precision was 0.41% and 0.61% for analyst 1 and analyst 2, respectively; accuracy between 99.23 and 101.79%; robustness between 97.13 and 98.45% for the quantification of M-PEGNC. Mean particle diameters were 261 ± 13 nm and 249 ± 20 nm, polydispersity index was 0.15 ± 0.07 and 0.17 ± 0.06, pH values were 5.0 ± 0.2 and 5.2 ± 0.1, and zeta-potential values were -37.9 ± 3.2 mV e -31.8 ± 2.8 mV for M-PEGNC and placebo(B-PEGNC), respectively. In conclusion, the proposed analytical method is suitable for the quality control of M-PEGNC. Moreover, suspensions showed monomodal size distributions and low polydispersity index indicating high homogeneity of formulations with narrow size distributions, and appropriate pH and zeta potential. The extraction process was efficient for release of meloxicam from nanostructured systems.

Electrokinetic Research on the Dispersion Behavior of Nano-Ceria Particles in Concentrated Suspensions

2015 ◽  
Vol 645-646 ◽  
pp. 394-399
Author(s):  
Wei Gao ◽  
Qi Long Wei ◽  
Ling Ding ◽  
Xiao Yuan Li ◽  
Chao Wang ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Rheological Properties ◽  
Concentrated Suspensions ◽  
Tem Analysis ◽  
Concentrated Suspension ◽  
Original Solution ◽  
Multi Scale ◽  
Scale Method ◽  
Dispersion Behavior ◽  
Significant Difference

A multi-scale method was developed, which utilized intrinsic relationships among zeta potential of particles, rheological properties of suspensions and particle size distribution (PSD), to analyze dispersion behavior of nanoparticles in concentrated suspensions. It was found that PSD of a kind of nanoceria particles by dynamic light scattering (DLS) method in solution A with concentration 5 wt% accorded well with that by direct TEM analysis, which meant the particles had been dispersed well. However, there had a significant difference when the concentration was increased to 20 wt%. When particles concentration increased from 5 wt% to 20 wt%, zeta potential in solution A changed from-150 mV to-100 mV, while zeta potential in solution B changed from-35mV to-45 mV. Variations of zeta potential of particles accorded well with rheological properties of suspensions too, from phenomenological models. When the suspensions composed by solution A and the nanoparticles with concentration about 20 wt% was diluted with its original solution to 5 wt%, the PSD of nanoceria could be measured indirectly, which accorded well with both that of a suspension prepared directly with near concentration and that from TEM images. Then a method to measure PSD of nanoparticles in concentrated suspension was brought forward.

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